Improvement in molds for concrete blocks



JOSEPH P. CAMPBELL.

lm prpvem ent in Molds for Concrte-Blocks;

9 l v J I 9 W I I J W 2 I l UNITED STATES PATENT OFFICE.

JOSEPH P. OAh LPBELL, OF DAYTON, OHIO, ASSIGNOR OF ONE-HALF OF HIS RIGHT TO JOHN M. PERRINE, OF SAME PLACE.

IMPROVEMENT lN-MOLDS FOR CONCRETE BLOCKS.

Specification forming part of Letters Patent No. 127,562, dated June 4, 1872.

Specification describing a certain Improved Mold for the Manufacture of Concrete Blocks, invented by JOSEPH P. CAMPBELL, of Dayton, in the county of Montgomery and State of Ohio.

My invention relates to a form of mold for the manufacture of concrete blocks, for paving or other purposes, with the sides tongued and grooved so as to interlock when laid together.

Figure 1 is alongitudinal section ofthe mold. Fig. 2 is an end view.

Arepresents the two sides of the mold, which are identical in form. The left ends E are recessed at a to embrace a portion of the triangular piece B, and thus sustained there is a pointed projection into the space 0. The inner corners of the right ends E are cut away so as to leave a triangular space, corresponding in form to the projection directly opposite, and being slightly smaller. On the back of the mold are secured wedge-shaped pieces m, which are beveled toward the center of the mold. On these surfaces the clamps D have a bearing, and as they are forced onto the wedge-shaped pieces the two parts of the mold are brought together and firmly held. At Fig. 2 is shown the position of the two parts of the mold when locked together.

The manner of handling the mold may be thus described: The triangular piece is placed in the notch for its reception; then the clamps are applied, which holds the parts of the mold securely together; then the material is put into the mold with a suitable tamp. On opening the mold a concrete block is removed, having its edges tongued and grooved.

For paving, building, and other purposes this form of concrete block would possess advantages over blocks having parallel sides.

To produce a concrete block tongued and grooved all around its sides, I set the mold onto a bottom-board having a projection corresponding with the point at B, and on the top of the mold I use a board having a triangular groove.

I line the inner surfaces of my mold with metallic plates.

I claim as my invention- A mold, for forming concrete blocks, having the recessed ribs A grooved, as shown, the triangular piece B, the dovetailed clamp I), and wedges m, all constructed and arranged to operate substantially as specified.

, JOSEPH P. CAMPBELL. lrVitnesses JOHN M. PERRINE, B. PIGKERING. 

